Monday, 28 October 2013

Bugs in the Plumbing

Earlier this year a PhD student working on a project in the Forestry Department for the Institut National de la Recherche Agronomique (INRA) posted a request on an entomology list server that I am a member of. He is studying whether the introduced Western Conifer Seed Bug Leptoglossus occidentalis has the potential to become a serious pest in Europe. His request was to those entomologists based in North America who could provide him with samples from the bug's native territory. He wanted to compare the DNA of these specimens to specimens collected in France, to determine exactly where the French ones had come from.

He received helpful responses from many of the list members based in the US and Canada. Several people said they had studied the species themselves and outlined their conclusions about its potential as an economic pest. It seemed that it was just considered a nuisance pest, as it has a habit of overwintering in domestic dwellings, but doesn't cause commercial damage, even in high value seed orchards (plantations where the crop is tree seeds for propogation).

Sucking Bug [IGP7706] (Leptoglossus occidentalis)
Photo courtesy of Tim from Aigronne Valley Wildlife.
That is, until a Canadian scientist mentioned that she had written a paper about the bug's ability to pierce plastic plumbing pipe! Everyone was fascinated, and the Canadian entomologist provided a link to her paper so we could read all the details.

She was invited to study the bugs after a manufacturer of plastic plumbing pipes started getting reports of weeping pipes. From the beginning there was a suspicion that it was the bugs causing microscopic holes, as they were always present when this problem was reported and when examined under magnification it was clear that the holes were being made from the outside.

Sucking Bug [PK70031] (Leptoglossus occidentalis)
Photo courtesy of Tim from Aigronne Valley Wildlife
Bugs were collected and put in boxes with various sorts of plumbing materials. Examination of the material showed that they had attempted to pierce everything -- all types of plastic and even copper. However, the only material they were capable of actually getting all the way through and causing a hole that leaked was PEX, an elastic polyethelene. These PEX pipes are 2mm thick and come in several colours. The bugs were not attracted to one colour over another, and there is no indication that they can sense the water inside. It seems that they instinctively try to pierce everything under their feet.

So, if you discover mysteriously weeping pipes in your home, search for Western Conifer Seed Bugs inside. We've had them in our house, in the spare bedroom (which is alarmingly close to the small bathroom, as Tim pointed out to me when I emailed him to ask for the photos). The species is quite common now in France -- but don't worry too much, their pipe puncturing activities seem to be fairly rare.
A la cuisine hier: Mussels, cooked in white wine with leeks, celery, garlic, parsley and thyme.
Nature News: I've had an email from Carolyn, a contact in Amboise, who tells me she has just been involved in some hunt monitoring on the weekend. Apparently there was a battue (beat style hunt) of Cormorants planned on the Loire near Langeais. The League Pour la Protection des Oiseaux (LPO) got wind of this and arranged for its supporters to be prepared to be there and record the activities of the hunt. At the last minute, probably because there were going to be television cameras there, the hunt was cancelled. The LPO has sent a strongly worded letter to the Préfecture pointing out that the Loire is a nature reserve which acts as a wildlife highway and dormitory for all sorts of species, especially migrants. The high numbers of Cormorants in the area at the moment are due to birds that have nested in Scandinavia making their way back south for the winter. The nearest fish farm to Langeais is 11 km away, so there was no justification for the hunt, even if one disregards the fact that the species is protected. Carolyn clearly rather enjoyed the experience and said it "Ended up being a good chance to meet some interesting people and in a beautiful setting." UPDATE: Here is a link to the TVTours video of the event.

I attended yesterday's fungi foray in the Forêt de Preuilly (fortunately the weather calmed down during the afternoon and we weren't rained on or at risk of being squashed by falling trees). Once I've catalogued my photos I'll write a post about the outing.


  1. Interesting fact to know. Never noticed that particular bugbut will keep a lookout in future. Fortunately all our plumbing is copper... C

  2. I've given Carolyn a "swift" response... but I think a talk like that would need to be specifically targetted.

    Seeing those pix makes me think that I need to scrub that front step into the Laiterie... it doesn't look nearly so pristine.

    Thought about joining you yesterday... but it was still raining here at 2:30!! But the wind had at least eased!!!
    All shuttered in here at the moment.... 5.4 Centipedes fell overnight and another two this morning...
    the Aigronne is Café Créme...
    and the cats are sulking 'cos I won't let them outside!!

  3. Tim: I'll be writing about swifts at some stage.

  4. I'm glad the LPO took action....I know that cormorants were becoming a nuisance on fish farms but that's a far cry from allowing them to be shot for 'sport'.

  5. A case of "shoot first and ask questions later" by the sound of it. It's good to know that there are people keeping tabs on things and looking after the welfare of wildlife.

  6. Jean, they did the same thing at an airport down south... and wiped out about 50 "farting ducks*"...
    another protected species and so rare that this act wiped out a third of the French population!!

    *[Little Bustards... the Latin translates as "Farting Duck"]

  7. Susan...
    are you going to do a LVN entry on this little fella?
    Just found one in the hooose... it is about to go out into the cold.
    We don't want crying pipes!!

    I've also got pix you can use of Reduvius... including a few really good pix of the camouflaged youngsters.

  8. Tim: no plans in the pipeline for an entry on these bugs. Thanks for the Reduviidae offer -- they are amazing little critters, aren't they?

  9. Can you please supply the link to the paper written by the Canadian in regards to stink bugs piercing water pipes. We have had this problem twice, so far, this winter and have had a plumber here to fix. Thanks

    1. The link I have won't work for you. Please PM me (email via my profile link on the right side bar). I will send you a pdf of the scientific note. The scientist was Sarah Bates and she published her observations in the journal of the Canadian Entomological Society Vol 137 2005.

  10. Fascinating, Susan! I've just recorded the first of these creatures in our garden here in the 17. Thankfully we do not have any plastic pipes that I am aware of!

    Your mention of the hunt though brings me starkly back to the present. I hate hunt season. I do not mind anyone who takes meat for the table, but the necessity to shoot at anything that moves still seems to be as rife as ever. How much meat is there left on a songbird after a charge of 12 gauge has gone through it? Rant over.....

    1. I've got a couple of friends who hunt and maintain good relations with them. However, I was not impressed a couple of years ago when some local guy advertised winter thrush shootig days at his orchard. I'm also not impressed by the badger hunt groups, whose attitude is appalling.